My interest in these oil system mods is purely academic. If I wanted to build a high winding engine, I'd go buy a racing block.
That said, I still cannot find anything which supports a bleed to help fluid turn. I'm talking raw physics here.
In manifold design there is definitely a momentum component to the flow which will tend to favor an excess of flow bypassing a branch. However, the bias depends on the fluid flow state. Motor oil is thick enough and moving slow enough as to be considered laminar flow. When flow is laminar, there's almost no momentum contribution and thus almost no bias at the fluid branch and so the division of flow is equal to the difference in the pathway cross sectional area.
Now, it's possible that at high rpm and with a hv pump that the Reynolds number enters the transition zone and flow becomes turbulent. But the thing is, the manifold (lifter galley) is properly designed because all branches T off and no flow "continues" out the front of the block.. And so there should be minimal bias at the branches.
There is some pressure recovery in turbulent flow when it passes a branch, that pressure recovery could be used to help bias more fluid into a second branch after the first. It has nothing to do with "slowing" fluid though "to help it turn". Instead there's a momentary rise in pressure after the first branch (assuming the cross over is to be placed before the #4 feed) which in that local zone would help boost flow into the next branch.
It's hard to describe, but again it's not anything to do with "slowing down to turn", but instead a rearrangement of energy in the flow causing a local pressure rise.
If I was an engineer trying to explain it to a nonengineer I might say "it slows down to turn" though, but that's not what's actually happening... Haha.